The objective of this proposal is to determine a sensitive indicator of methyl methacrylate toxicity. We propose to confirm our previous observation that rats exposed for three months to the monomer vapor demonstrated significantly lowered average body weight and absence of body fat. We also propose to determine whether this phenomenon is age-dependent. It is further proposed to determine whether short term exposure to the vapor can be associated significantly with changes in gastrointestinal motor and absorptive functions, with various plasma lipid concentrations, fat pad constitution, blood glucose concentration, liver glycogen content, blood acid base parameters, weight gain, and food intake. Ultrastructural examination will be made of gastrointestinal and liver cells from exposed male, Sprague Dawley rats.